Collaborative Research: Resource ratio effects on stream detritus and detritivores

University Of Central Arkansas, Conway AR

Investigators

Abstract

Anthropogenic nutrient enrichment of ecosystems is a global phenomenon that often negatively affects ecological communities leading to lower biodiversity. Elevated nutrients can alter the proportion of nutritional elements such as carbon and phosphorus in food resources and can influence the diversity and type of species present in ecosystems. Many aquatic species have evolved to use low quality leaf litter as food resources (i.e., detritivores); these species are adapted to a diet that has a high ratio of carbon relative to phosphorus. When phosphorus levels in food resources are elevated, as is often the case in human-enriched aquatic ecosystems, the growth of some detritivore species may be negatively impacted due to an increased energetic cost of eliminating excess phosphorus from their bodies. This counter-intuitive, negative effect of elevated nutrients on consumer growth may lead to the loss of detritivore species from aquatic ecosystems. This project will determine whether changes in the ratio of carbon to phosphorus in detrital resources result in predictable effects on growth of insect detritivore species across an enrichment gradient in Ozark Highland streams. The research will combine laboratory experiments with an analysis of a regional data set on stream ecosystems to determine whether anthropogenic phosphorus enrichment of detrital resources is having direct negative effects on aquatic detritivore species diversity. Results from this project will provide a more thorough understanding of the ways that nutrient enrichment can impact stream systems, information that is useful to improved management of these ecosystems. Through outreach to watershed groups and state agencies, the results of this research will be communicated to the local community and natural resource managers. The proposed activity will support research training and career development of graduate and undergraduate students, including members of under-represented groups. This project represents a collaboration of two beginning investigators from a research university and a primarily undergraduate university.